Friday, June 18, 2010

Diesel VS Electric drive...

On a forum recently, an internal combustion fan pointed out some facts on why electric propulsion is dumb or at least not ready for prime time... Off hand I don't really like the whole this vs that sort of thing as in this case it is really not diesel VS electric propulsion but more a Luddite knee jerk reaction vs a different way of thinking.

  • You can run a small diesel for years on end with little maintenance.
That's not my experience or judging from my many friends with diesel and gasoline engines... Like everything on a boat, stuff needs to be maintained and whether you choose electric or IC systems you are going to have to maintain it and if you don't, well you will most likely find yourself in a world of hurt of one sort or another.

One of the things I really like about electric drives is that they are clean and working on them is a pretty much non-messy affair. Of course, the other thing I like about electric drives, me being Mr. Cheapseats, is that my whole system costs less than most dieselheads spend on oil changes, filters, gaskets, and the odd fuel pump or part and, we can't forget that diesel costs money as well...
  • You can light with diesel
Here I'm guessing that he means that you can produce electricity with a diesel by running your engine which is not really designed for running lightly loaded and increase the wear and tear and the need for more of that maintenance you don't have to do (see above point) on diesel engines...

That said, most electric propulsion systems these days are able to regenerate electricity so while you are sailing you make electricity which fills your batteries and then you can use it for lights, computers, or that HD-TV...
  • You can heat with diesel.
Sure you can... You can also heat with propane or wood but I'm not going to go out and get a wood-fueled engine anytime soon (though with peak oil it might not be a bad thing for those with diesel systems to look into...)
  • You can cook with diesel.
Sure you can... I've lived with a diesel and a kerosene stove. Life is simply too short for that kind of hassle and having everything on your boat (including you) smell like oil/kerosene does not get you invited over for the good pot-luck dinners!
  • You can run a watermaker from it.
Then again, you can also run one off of solar panels and more than likely if you are like most folks on a boat, you really don't even need a watermaker (do the need/want exercise). If I do decide to install one, I can run it off my 12V or 48V bank and use the energy that my electric motor regenerated to make water...
  • You can run a generator from it.
Seems we are back at being able to make light (see point #1) and cause excess wear on the engine... But yeah, if you need lots of power and are smart you may want to run a genset and gensets do make sense for making power... We have a Honda 2000i on "So It Goes" and I can make all the power I can use for less than a liter of gas per hour. Which, by the way, brings up a personal question: why would anyone actually need a 16KW Genset on a cruising boat? Maybe they run all their tools at the same time or who knows what?
  • You can run an air conditioner from it.
I suppose so... Off hand, I simply do not see air conditioning as a needful item and most folks I know who do, never seem to leave the dock, in which case the shore power cord works finest-kind!
  • You can run a fridge from it.
Yep... I can also run my fridge from solar panels, a wind generator, regen, or my Honda... So what is the point? Well to me, the point is that people are still not getting it. With dwindling resources and fossil fuels going the way of the Dodo, it is time to try and simplify and use less. Maybe having a boat that has to constantly run its motor to keep up with its huge electrical loads just might not be the smart move in these fast approaching hard times. As someone who holds a lot of respect for "Murphy's law", I most certainly do not want to make all my systems dependent on any one thing... With this guy's mindset, if he finds himself in a place where he can't get fuel he is in the dark reading with a flashlight and his beer is not going to be cold... Or, if he happens to find himself needing a part, his beer is still going to be warm and so on... For those who "get" the idea of electric propulsion it is all something of a no-brainer and quickly becomes an integrated part of the boat in a balanced way... and folks, balance is a good thing! For those who don't get it, I'm not sure I can really explain it to them and I may be just preaching to the choir...

On the other hand, as I have said more than once, electric propulsion is not a panacea or for everyone. Sure it has its advantages but it also requires you to be flexible and to use your resources wisely and if you are not, it can ruin your whole day (you might even have to drink warm beer and read by flashlight).